Conventionally, an electronic part compression bonding apparatus has been known which mounts electronic parts, each formed by a film-shaped member, onto a substrate made of glass or the like. This apparatus has been known as an electronic part compression bonding apparatus for manufacturing a flat panel display typified by a plasma display panel (PDP).
FIG. 1 is a plan view showing an example of a glass substrate on which electronic parts are mounted by an electronic part compression bonding apparatus, and FIG. 2 is a side view thereof. The glass substrate 1 shown in FIGS. 1 and 2 is formed by adhering two types of substrates 1a and 1b having different sizes. In FIG. 2, a plurality of electronic parts 2 are mounted on the bottom surface of the upper substrate 1a and the top surface of the lower substrate 1b, respectively, along lines of each of the substrates 1 through anisotropic conductive films (hereinafter, referred to as “ACF”) 3.
In the electronic part compression bonding apparatus for manufacturing this type of glass substrate, the ACFs 3 are adhered on the glass substrate 1 along the lines where the electronic parts 2 are mounted. Thereafter, the electronic parts 2 are preliminarily attached to the glass substrate 1 by the use of adhesiveness of the ACFs 3. The preliminarily attached electronic parts 2 are then heated and pressed to the glass substrate 1 using the electronic part compression bonding apparatus, thus connecting leads formed on the glass substrate 1 and those of the electronic parts 2.
FIG. 3 shows an example of a conventional electronic part compression bonding apparatus 10. The electronic part compression bonding apparatus 10 is provided with a long compression tool 13 which is raised/lowered by a pressure cylinder 11 and has a built-in heater 12, and a back-up tool 15 as a pressure receiving tool which is located to face the compression tool 13, raised and lowered by an unillustrated lifting means and has a built-in heater 14.
Next, a compression bonding procedure by the use of the electronic part compression bonding apparatus 10 is described.
First of all, the glass substrate 1 where the electronic parts 2 are preliminarily attached is put on an unillustrated substrate stage. The line on the glass substrate 1, which should be bonded with the electronic parts 2 by compression this time, is positioned to face the compression tool 13. Next, the back-up tool 15 is raised and supports the glass substrate 1 from the bottom, and subsequently or simultaneously, the compression tool 13 is lowered by the pressure cylinder 11. Accordingly, by pressure applied from the pressure cylinder 11 and heat from the heaters 12 and 14, the electronic parts 2 preliminarily attached to one of the lines of the glass substrate 1 are bonded at once to the glass substrate 1 by thermocompression through the ACFs 3. Upon completion of this thermocompression bonding, the compression tool 13 is raised and the back-up tool 15 is lowered.
Thereafter, if there remain lines on the glass substrate 1, where the electronic parts 2 should be bonded by compression, the line of the glass substrate 1, which should be bonded with the electronic parts 2 next, is positioned to face the compression tool 13 by driving the substrate stage.
On the other hand, if there remain no lines on the glass substrate 1, where the electronic parts 2 should be bonded by compression, the glass substrate 1 on which the electronic parts 2 are completely bonded is whisked off the subsequent stage. Thereafter, the electronic part compression bonding apparatus 10 receives a new glass substrate (i.e. a glass substrate to which the electronic parts 2 are preliminarily attached) 1 from the preceding process and repeats the compression bonding operation mentioned above.
Incidentally, the film-shaped member that is a base material of each of the electronic parts 2 is made of, for example, polyimide resin. Therefore, it is known that the electronic parts 2 elongate during thermocompression bonding thereof by the electronic part compression bonding apparatus 10 described earlier. Thus, the electronic parts 2 are made to have relatively small dimensions, allowing for elongation thereof during thermocompression bonding.
However, the elongation amount required during the thermocompression bonding is different for each type of the electronic parts 2, more specifically, for each of the thickness, size, shape and the like of the film-shaped member. Therefore, it has been difficult to satisfactorily adjust the amounts of elongation which occurs during the thermocompression bonding, with respect to various types of the electronic parts 2.
When the actual amount of elongation which occurs during the thermocompression bonding is different from a required amount, the electronic parts and the glass substrate may be poorly connected to each other, and this has been a disadvantage.
Meanwhile, one trend is that leads of the electronic part 2, which are to be connected to the leads of the substrate 1, are becoming increasingly fine-pitched as a flat panel display and the like has become highly functional. Therefore, there has been a demand for an improvement in accuracy of thermocompression bonding by the electronic part compression bonding apparatus 10.